Compared with the conventional trench MOSFETs, super-junction trench MOSFETs are more attractive due to higher breakdown voltage and lower specific Rds (drain-source resistance). As shown in FIG. 1, U.S. patent application Ser. No. 13/751,458 of the same inventor as the present invention discloses a super-junction trench MOSFET 100 comprising a termination area including multiple guard rings (“GR”, as illustrated in FIG. 1), wherein the termination area is about 200 um in length due to the multiple guard rings. However, for the integration of semiconductor power devices is more and more advanced, a super-junction trench MOSFET with short termination is admired because it takes up less space and is more cost effective due to its smaller device size.
Therefore, there is still a need in the art of the semiconductor power device, particularly for super-junction trench MOSFET design and fabrication, to provide a novel cell structure, device configuration and fabrication process that would resolve these difficulties and design limitations.